Expendable lead line sounder



April 4, 1961 F. N. D. KURIE ET AL 2,978,690

EXPENDABLE LEAD LINE SOUNDER Filed April 10. 1955 4 Sheets-Sheet 1 l I8 I INVENTORS F. N D. KUR/E L. 14. CARTWR/GHT ATTORNEYS 4 Sheets-Sheet 2 F. N. D. KURIE ET AL EXPENDABLE LEAD LINE SOUNDER A ril 4, 1961 Filed April 10. 1953 INVENTORS E/V. D. KUR/E L. 14. CARTWR/GHT BY M i {I ATTORNEYS April 4, 1961 F. N. D. KURIE ET AL 2,978,690

EXPENDABLE LEAD LINE SOUNDER Filed April 10. 1953 4 Sheets-Sheet I5 IN VEN TORS F. /V. D. KUR/E L. A. CARTWR/GHT ATTORNEYS April 4, 1961 F. N. D. KURIE ETAL EXPENDABLE LEAD LINE SOUNDER Filed April 10. 1953 4 Sheets-Sheet 4 RTWR/GHT BY L A CA ATTORNEYS flh' a c mpanying: d wing I'e1d/lfhe1'6in; 11st: tmg.one;prefe1redem- 3 bodi nyent-iontwithaa portion,of,;the

United 2,918 620 EXPENDABLE LEADzLINE :SOUNDER Franz N. D. Kurie,,Alexai1 dria, Va and Louis A. Cartht. an ,v .(l l f-mssigmtstMh Un t d' t of America as represented by the Secretary of the lflayy Filed Apr; 10, .1953, Serhim-348,142 a ms- 9.-2 (Granted underTitleSS, U.S. '.Gode. (-1952), sec. 266) .nnitter, 'lead' :line' depth-measuring apparatus and. electric batteries allmounted5in;-an-.elongated .bugy. adapted ;to be :launched fromlan .aircraftandgfioatt-pprjght onthet-s urface .of the water. :The;1buoy.- supports airadio. autennaat its :upper end and. contains a. sounding rlead attached to one .end of aline which is woundgaroimd a-reel. gearedto a r.

potentiometer. When the"buoyssstrikesi the water, the :Eimpa'ct-releases: the lead-weight which zu'nwindsazlthe line .from F the *reel and. varies. ithe. resistance...acrosspthe .po-

-;tentiometer. :.The:; potentiometerilisjtincorporated. in an z-elcctronic circuit in a :manner. which controlsrthemodula- -.tion frequency of.ithe' transmitted radio signalimprorportion .to the lengthcof. Fliue ereeled-outbefore $116; .weight Strikes: the bottomor reiachesathe endof-.the.line.' :Suitable -.mechanism is} ,prOVidedCfOI'; locking: the. ,1reel,.twhen the weight has j reached .ttheab ttom. Also. included in. the 1 P esent l invention. :is mot-related zapparatusqafor ::use with a conventional receiver andicooperating with: depth I measuring :apparatus incorporated in Ihedbuby toaindicate 1 heidepth. ata-remotestation such-as thedaunchingair- ;c'rafl. This indicatingapparatus:is essentially a frequency' easuring-tcircuittwithua meterzcalibratediin.zfathorns or otherdesi ablettunits.

tp a :tor r liablytand aceumtelwmeasuring-andindication-marl: est ed, 7 any.fifithezattendant advantages of :bet e u d li$i fidjiby .ireference no the following detailed;,description;when wonsidered;in. E-connection with Ei a wisa pictorial vie.

went q he ese -2i br ken-1 a yst ow; th iii-nteiior arrangement of I .Figg 2- =is agpictorial -.viewt =.of;tl 1e,;re el. with the associated er e r s s em ahdipcte met r;

fan a the iewpnic D seas a d;

"EIg SJi a schematic circuit .tates atent Y- :Qne object-{of .atherptesentqinvention fis ltmprovide tapg' t e d piht f' 1?=at::&ny..position where such infor- "sdnventiondvill bereadily appreciated asz-thesaihe be- .ee equo th siestts 2,978,690 Eatented Apr i4, 196} electronic apparatus 20. j A release mechanism 21 actuateing a switch (not shown) may be utilized to connectihe electronic apparatus to the power supply consisting of batteries 18,:before it is launched'fro'm' an airplane or other craft. A closure {22. is adapted to be openedsubsequent to launching the buoy to release a parachute (not shown) which serves to ,slow the speed of the descent, if the device is dropped from an airplane, and alsotends to drag inthe water and serves to some extent asa sea anchor or drogue for stabilizin the device while floating inthevvate A. b go .dy =24 m y e ti wt h fhll y and :stains thelwaterisurrounding 1itpto{facilitate yisual observation .Of the position. Y

A lead or other-heavy weight 4.:issuitablym t t at the lower end f t ebuuy and is hrovid dwi h a plate 23. having. an..ear- 30 extend ng into an .onenin and, a latch 34.pivotallymountedwat 236i .ehgagingithe vhatch v38 .for retaining the weight imposition during-the r p- Up 1. impact the w ight moves upward y tolr ease the latch 34 from the, cat h 38 pe m tti g the pri 140 to move the latch into the. retracted position shown in dotted lines. The springAZ engaging. in a recess- 44 serves to ejectqtherweight after the:-latch- ;s;4ljis released.

A line .476 connected at one endto the Weight 1 wound around the reel 48 which is suitably mountedmn .a bracket .50 s curedlto he body 12 by suit b e ifastening means suchas thescrevvs,52,f54 and; 5;6'. The ratchet w h eel 58 mounted on one end-10f the reel; shaftlfill is pr vide w h a pair of oP'PQsitely disp sed cut-outper- 'tions 62 and 64, each provided withanotch-ddand-GS re pe ive y. A.,detent sp i g 70 i adaptedv to rideon h 'rat het,wlieel;58 .in he position shown in solid lines in ig- 3 andmoyesthe ratche whe l bac wards tothe dotted line position ,after'Jthe Weight strikes the bottom ';;dueto :the lifting of the/.buoy :by'the waves .01 ,Qthfi 1 o i n -.whi h .will pull-the line vd6 enough to "bringone of the notche .62 under the spri g 70 an permit ;the

t 1; etto lock. Spring 'Ztlis mountedina suitable clamp 76, 7.8, and- .80 aremounted onithe ion tolehg gethe reel, andise'rve to aeworm gear 92] attached {to thegshaft193 of' potentibmter 182. V The rewind gknob ;24 n1ay be 'proyided, T ifj tde'sired,

for laying the line on the reel, andalso .fgrsrewindingjthe 1 line, when the devifie may be recovered to; be used again.

fli e'el t. c-app atu u l zed.totrausniitt e. gn ca ry n .t t l en e. is i lustrated sshematically in g. .4, w re h t e p i met r .82 is indi at ischematically in the. voltage divider circuit also containing gthe yoltage regulator tube 102' which may be of a neon gasdischarge; typeyyariableresistors 194 and 106 which are ut lizedto -.adiu ihent e the cir uitand fixed resistors oteht pm teritihavh his e r d enema 48. controls 1,... freque y oiarm ibrator circuitbyvarytn agthe fiQliillk 'QM Eha eQ skie -White wont-t1; sie idsap tubesdM-ahd.116; ca

denser 117 maintains the bias voltage above ground potential. Resistors 118 and 120 are the plate load resistors of tubes 114 and 116 respectively, while resistors 122 and '124 constitute the grid bias resistance for the grid of tube 114, and resistor 126 is a grid bias resistance for tube 116. Condensers 128 and 139 are charged and discharged through the resistances 124 and 126 respectively in a conventional manner to actuate tubes 114 and 116 as a free-running multi-vibrator. Capacitors 132 and 134 together with resistors 136 and 133.couple the signal from multi-vibrator tubes 114 and 116 to the modulator tube 140 in a conventional frequency modulation transmitting circuit. Capactior 139 is an RF by-pass condenser.

The reactance modulator tube 140 functions as a variable reactance connected in parallel across the tuned circuit of the radio-frequency oscillator tube 142. A por tion of the RF oscillator voltage is fed back to the grid of the reactance tube 140 through a phase shifting net-' work which shifts this voltage 90 in phase with respect to the voltage across the oscillator tank. The voltage applied to the grid of the reactance tube causes plate current to flow, which is in phase with the grid voltage and 90 out of phase with the RF voltage across the oscillator tank. For this reason, the voltage developed across the plate-load resistor is 90 out of phase with the RF oscillator tank voltage, and the; reactance-tube circuit thus acts as a reactance shunted across the tank circuit of the oscillator. The magnitude of this reactance with no signal voltage applied to the grid isdetermined by the grid bias of the reactance stage. a This reactance value, in combination with the reactanceelernents of the oscillator tank circuit, determined the mean oscillator frequency. When I the signal is applied to the grid of the reactance tube, it,

' son this value, :75 kc., has been arbitrarily chosen as the standard to represent 100% modulation. In PM the term 100% modulation dilfers entirely from the meaning associated with it in amplitude-modulated transmitters. For AM, 100% modulation refers to the greatest degree of modulation that can be applied to a carrier wave without resulting in distortion. In frequency modulation, 100% modulation corresponds to the frequency deviation for the loudest signals to be transmitted. This is determined by the design of the equipment and is not limited by distortion as in amplitude modulation.

In carrying out the present invention it is preferable that the frequency deviation of the oscillator produced by it the reactance modulator for 100% modulation be $18.75 kilocycles from the mean oscillator frequency. Since the oscillator frequency is doubled twice in the following stages, the final frequency deviation of the transthe tank circuit and the grid of the reactance tube. The portion of the RF oscillator tank voltage is shifted 90 in phase and applied to the grid of the reactance tube through this circuit. Resistance 152 is a plate load resistor for tube 140 and resistor 154 is the de-coupling resistor in the plate voltage lead. Capacitor 156 is the bypass condenser for the screen grid, and capacitor 158 is the coupling capacitor between the plate circuit of the reactance tube 140 and the tuned circuit for the oscillator which consists of an inductance coil 160 and a condenser 162.

The control portion of the oscillator is a conventional Hartley circuit utilizing the pentode tube 142 as the oscillator tube and also as one stage of amplification. The screen grid, control grid, and filament of tube 14-2 are used in the actual oscillator control circuitand the signal is amplified in the plate circuit. The radio frequency energy from this control circuit is coupled to the plate output circuit by means of the cathode plate current electronic stream. Byusing an electronic coupling the control section of the oscillator is electrically isolated from the load portion of the circuit. This results in a greater degree of frequency stability under varying load conditions.

The tuned circuit of the oscillator control section consists of inductor coil 160. and capacitor 162. The resonant frequency of this type of circuit is preferably approximately 17.5 megocycles for, the reasons stated supra. The tuned circuit hasa high Q and capacitor 162 preferably has a negative temperature coefiicient. These factors provide good frequency stability at this high radio frequency. The operating frequency of the control section is adjusted by varying the inductanceof coil 160 by means of the movable polyiron core of the inductor. The bias of the oscillator is determined by the values oi capacitor 164 and resistor 166.

The two halves of the filament of the oscillator tube 142 are connected in parallel. The filament must be maintained at RF-potential above ground for the cricuit to function properly. When both sides of the filament are maintained at the same RF potential, maximum power output is obtained from the oscillator. To assure that the positive andmegative ends of the filament halves will be at the same RF potential, a four-turn coil 168 is connected to the positive A-battery lead. and by-passed to ground by condenser 170. The other end of the coil is connected to one terminal of the parallel filament sections. The

induced RF voltage in this extra winding is thus applied to the positive terminal of both halves of the. filament.

The center tap or other end of each half of the filament is connected toa tap on coil 160, four turns up from the ground end. From this tap on coil, 160, an RF voltage,

. equal to and of the same-polarity with respect to ground as the voltage in the extra coil, is applied to the negative terminal of the filament. These voltages being equal and of the same polarity result in the entire filament being maintained at a constant RF potential above ground.

mitted RF signal would be i kilocycles, i.e., 118.75

kc. 2 2- L75 kc.

The input-circuit of the reactance modulator tube 146 is made up of resistors 138 and 1 44 together with capacitor 134 which couples the signal voltage to the grid circuit. Resistance 13% acts as an isolating resistor and with the resistance 144 forms a grid leak resistor. Resistance 146 is a bias resistorjor the reactance tube. The bias voltage is developed across this resistor by the flow of the plate current from all the tubes in the transmitter through resistance 146. This voltage is of sufiicient magnitude to bias the reactance tube 146 to the desired operating point. Resistor 148,.capacitor 15:0 and the grid to cathode capacity of tube form the phase shifting network between Capacitor 172 is the RF by-pass condenser for the screen grid of tube 142 and resistor 174 is the screen dropping resistor. Theoutput'circuit of tube 142 is composed of the fixed capacitor 176 and the variable inductance coil 178 constituting a tank circuit the fre quency of which is tunedto the second harmonic of the oscillator control-section which would preferably be approximately 35 megacycles. Tuning is accomplished by varying the inductance of coil 178 by means of a movable polyiron core. Capacitor 180 is an RF by pass condenser for the platehigh-voltage lead.

A pentode vacuum 'tube 182 serves as the radio frequency power amplifier and frequency doubler. The out I put of the electron-coupled oscillator-doubler is coupled to the grid of tube 182 by a capacitor 184. Resistor 186 is the grid ,bias resistor for tube 182, The screen grid dropping resistor 188 .and the screen RF by-pass condenser190 perform their normal functions.

, series-triode side of the indicator tube.

of tube 218 is tied to the triode plate and controls the' fiow outn tinlate eircuittcfz tube; 18 .;is .thetua shtank consisting f h xedicapa iten-122mm: h variable inductor 194.- Capacitor 192 is preferably a silver-mica capacitonwithane'gative temperature coetlici'entiand coil 194 is a variable indnctorztuned byra movable polyiron ogre. This,resonant circuit is' tuned to twice the input frequency and-willpreferably be approximately 70 -mega'- Gyeles; Since the input circuit andbutputcircuits operate .on such widely different frequencies, there is no need for neutraligation. Capacitor 196 is an RF by-pass condenser used to keep the B+ lead of coil 194 at RF ground-potential.

The: antenna coupling coil 198 is wound as a second winding on'coil 194 and-in conjunction with the antenna loading coil 200;and the-v,ariahle capaeitor 202 it serves to couplethe output of the doubler amplifier to the antenna '204. Tuning is accomplished by varying the capacity of condenser "202 until the coupled circuit is in r s nance a h t ansmi er. reque ew Batteries are most t e e satil used o. suppl a l of the required electrical power and shouldbesuflicient 'to operate the radio transmitter and the multi-vibrator circuits for a substantial length of time depending on the particular use of the device. The A-battery power sup ply 206 preferably consists of a plurality of dry cells connected in parallel to supply the voltage for the fila' ment circuits and will ordinarily supply a' filament voltage of approximately 1% volts.

The B-battery power supply 208 preferably consists of two or more high voltage miniature B-batteries connected in series to supply the voltage for the plate and screen grid circuits of the transmitter and the multi-vibrator circuits. The total output voltage of power supply 208 nore mally is approximately 135 volts.

- The power is turned on and off by a double-pole singlethrow spring-actuated switch 210 which is released for closing the circuit when the buoy is launched from the plane or other station, by the release mechanism 21'not disclosed in detail in the present application. Condenser 211 is a by-pass condenser for radio frequencies from the B+ side of power supply 208 to ground.

Theschematic circuit diagram of Fig. illustrates one preferred embodiment of apparatus to be used in conjunction with a conventional FM receiver circuit (not .shown) for indicating the depth of water at a remote station in conjunction with the. apparatus of Figs. 1

through 4 fordetermining the depth and transmitting a,

frequency modulated radio. signal. I

The conventional FM receiver will normally-receive and demodulate the radio signal and its output signal will have a frequency correlated to the depth of water and corresponding to the frequency output of the multivibratorcircuit including tubes 114 and 116. "This output signal-is supplied to the. primary winding of trans-5 I former 212 in Fig- 5 and is also coupled through resistor 214 and capacitor 216 to' the grid of a conventional electron ray indicator tube 218 which serves as a visual signal indicator to show when there is suflicient signal a strength for proper operation.

Resistor 220 is the grid bias resistor-for the triode grid of tube 218 and resistor 222 is the load resistor in the The secondgrid of electrons to the target 224. v V i Capacitor 226 is a by-pass condenser and variable resistance 228 is connected to the center tap on the secondary winding of transformer 212 for maintaining the desired negative operating bias on the-grids of gas triode tubes 230 and 232,-the signal being applied to the grids from the secondary winding through resistors 234and' 236 respectively. These thyratron tubes 230 and 232 operate through an RC discriminating circiut consisting offlcapacitors 238, 240 and 242 and resistors 244, 246, 248 and 250, and through a duo-diode tube 252 into a vacuum tube bridge consisting of pentode tube 254 and a d es stor 272v in. 9ni1 n t n with: a oltage. e ulato tube 274.

Suitable switches 276, and 27,8,and pilot lamps 280 and 282 areprovided to performv their norm-alffunct n's,

Q u m mb ifi i ns and r a ions Q... the P sen n nti e. pos b e. n the l ght of the. ewe ea-thi .gs- It s there e e t e. underst od. that were th scene ofthe appended. e aims heiay ntiea ma be pra ice otherw se t an s e ifically e cr ed, 0 What is claimed is:

1. In combination, depth sounding apparatus including a Weighted line extended from the surface to the bottom, a potentiometer operatively associated with said depth sounding apparatus and adapted to be varied thereby in accordance with the depth measured by the extended length of said line, a frequency modulation radio trans mitter, and a free running multi-vibrator circuit associated with said transmitter for modulating the mean frequency thereof inaccordance with the operating frequency of the multi-vibrator circuit, said potentiometer being connected in said multi-vibrator circuit for varying the operating frequency thereof to produce a signal having a frequency proportional to the measured depth and an electronic circuit adapted to be used in conjunction with a frequency modulation receiver and including means for indicating the depth corresponding to the signal frequency, said indicating means including an electron tube inverter operating into an electron tube bridge 7 through an RC discriminating'circuit'and a direct current milliammeter calibrated to indicate the depth connected across said bridge.

2. In combination, depth sounding apparatus comprising a buoy, a reel rotatively'mounted' in said buoy, a' weighted line mounted on said reel and adapted to be played out. by gravity thereby rotating said reel until the line contacts the bottom, a potentiometer rotatively linked to said reel and adapted to produce a variable impedance and an electronic circuit adapted to be used in'conjunction with a frequency modulation receiver and including means 2 for indicating the depth corresponding to themodulat ed radiosignal, said indicating meansincluding *a meter 5 Y calibrated to indicate the depth measured.

v 3. In combination, depth sounding apparatus includin a weighted lineextended from the surface to the bottom,

- a variable impedance operatively associated with .said

depth sounding apparatus and adapted to be varied thereby in accordance with the depth measured by the.

extended length of said line, a frequency modulation radio transmitter, a multi-vibrator circuit associated with said transmitter for modulating the mean frequency thereof,

said impedance being connected in said multi-vibrator circuit for varyingthe operating frequency thereof to produce a signal having a frequency proportional to the meas ured depth, and an integrating electronic circuit. adapted to be used inconjunctionwith a frequency modulation receiver and including a meter adapted to measure the 7 current through a portion of said circuit wherein the current is proportional to the signal frequency, said meter being calibrated to indicate the depth measured by said measuring means. 7

4. In combination, depth sounding apparatus including a weighted line extended from the surface to the bottom,

.a variable impedance operatively associated with said depth sounding apparatus and adapted to be varied thereby in accordance with the depth measured by the extended length of said line, a frequency modulation radio transmitter, a multi-vibrator circuit associated with said transmitter for modulating the mean frequency thereof, said impedance being connected in said mu1ti-vibrator circuit for varying the operating frequency thereof to produce asignal having a frequency proportional to the measured depth, and an electronic circuit adapted to be used in conjunction with a frequency modulation receiver and in- .cluding means for indicating the depth corresponding to the signal frequency, said indicating means including an electron tube inverter operating into an electron tube 8 bridge through an RC discriminating circuit and a depth indicating meter across said bridge. a a

References Cited in thefile of this patent UNITED STATES PATENTS OTHER REFERENCES Pickering: The Radio Sonde, Proc. IRE, vol. 31, No. 20 3, pages 479-485 (September 1943); 

